init params as null

I started gettting odd exceptions, so I thought this should be null and not on the stack or pointing to garbage. I might be totally in the wrong here.

WiFiManager.h

@@ -363,7 +363,7 @@ class WiFiManager
     // WiFiManagerParameter
     int         _paramsCount          = 0;
     int         _max_params;
-    WiFiManagerParameter** _params;
+    WiFiManagerParameter** _params    = NULL;
 
     // debugging
     boolean       _debug              = true;